Master of Science (M.S.)
Degree Granting Department
X. Peter Zhang, Ph.D.
Jon Antilla, Ph.D.
Edward Turos, Ph.D.
Shengqian Ma, Ph.D.
aldehyde, azide, catalysis, chiral, cobalt, porphyrin
Medium-sized organic ring synthesis poses a seemingly insurmountable challenge, and because of this it is a field under immense investigation. Heterocyclic containing medium-sized rings are common structural motifs in nature, which has caused researchers to investigate their potential biological activity and properties as materials. This research focused on the grand challenge of medium-sized heterocyclic ring synthesis, providing the synthesis community with new tools to generate these highly evasive products, while elucidating energetic and geometric properties of one of Nature's least understood organic ring systems.
Cobalt(II)-Amidoporphyrins, [Co(D2-Por)], are an emerging class of metalloradical catalysts (MRC) which can facilitate a wide range of atom and group transfer reactions. A strategy was employed using [Co(D2-Por)] to carry out an intramolecular C-H amination reaction using sulfamoyl azides as the radical nitrene source to aminate the highly reactive aldehydic C-H bond. This newfound reaction allowed for the generation of previously unobtainable medium-sized heterocycles, which surprisingly provided a racemic mixture of chiral medium-sized rings.
A wide array of chiral amidoporphyrins including meso-heteroatom containing porphyrins were synthesized as well during the course of research to probe their potential as new chiral ligands for the emerging field of cobalt(II)-amidoporphyrin catalyzed MRC system. A practical synthetic scheme was discovered employing the highly selective Zn(II)-bromoporphyrin synthon to generate a new library of chiral amidoporphyrin ligands for the MRC system through well-established cross-coupling methodologies.
Scholar Commons Citation
Lizardi, Christopher Lee, "Aldehydic C-H Amination Reactions via Co(II)-Based Metalloradical Catalysis and Construction of Novel Chiral meso-Amidoporphyrin Ligands" (2015). Graduate Theses and Dissertations.